European Journal of Cardiovascular Medicine

Worldwide, more than 20 million patients suffer from Inguinal hernia and undergo elective repair yearly [1,2] with a low probability of recurrence and complications [3], the most often performed surgery               is Lichenstein’s tension- free repair.  Laparoscopic Transabdominal Preperitoneal Repair (TAPP) and Total Extraperitoneal Repair (TEP) occurred as a result of the evolution of surgical technique and the introduction of novel surgical platforms [4,5].The Goal of these procedures is to reduce the hernia sac and the contents and to repair the abdominal wall defect[6,7]. In TAPP procedure the surgeon enters the peritoneal cavity, incises the peritoneum, enters the preperitoneal space and places the mesh over the hernia defect, the peritoneum is then sutured. [8,9,10] In TEP procedure, peritoneum is not opened, Here preperitoneal space is created and mesh is placed in the preperitoneal space which reduces the risks of TAPP caused by entering the peritoneum such as infection, adhesions, perforation and organ injury. [11,12,13]

Based on the recommendations from the Preferred Reporting Items for Systematic Reviews (PRISMA) [14], a systematic review was carried out. The Pubmed, Embase, And Cochrane Library search engines were used. The search was conducted till December 31, 2023. The terms "Inguinal," "Hernia," "Herniorrhaphy," "Mesh," "Prosthetic material," "Laparoscopic," "Transabdominal Preperitoneal" (TAPP), and "Totally Extraperitoneal" (TEP) were combined to create the following MeSH terms (Medical Subject Headings). References, abstracts, and titles were assessed.

ELIGIBILITY CRITERIA AND STUDY SELECTION

Trials comparing TAPP with TEP repair that were observational studies and randomized controlled (RCTs) were considered for inclusion. The number of defects (unilateral or bilateral disease), the site of the defect (inguinal,or femoral hernia), the type of hernia (direct, indirect, or combined hernia), the status of the hernia (reducible, strangulated, or irreducible hernia), the type of intervention (elective or emergency surgery), the size of the study population, demographic information (sex, age, and health status), the follow-up Period, and the studied outcome measures (all of these questions) were not the parameters for excluding the study.

Figure 1: Study Flow According To Prisma Guidelines

DATA EXTRACTION

The following information was obtained: the author, the publication year, the country, the study design, the number of patients, the sex, the age, the body mass index (BMI), the surgical technique, and the early postoperative results. Three investigators independently entered all of the data; comparisons were made only after the review process. A fourth author (GC) eventually reviewed the database. Discrepancies were clarified

SEARCH RESULTS AND STUDY SELECTION

A total of 128 records were identified through the electronic search of the databases. Based on the abstract, 36 articles were discarded as nonrandomized studies 67 duplicate studies were identified in the searched electronic databases. 25 articles were screened for the final process out of which 13 were excluded with reasons. A total of 12 articles fulfilled the eligibility criteria and were included in the meta- analysis

OPERATIVE TIME. Ten studies were reported on operative time between TAPP repair and TEP repair. The data of 791 patients revealed significant differences between the TAPP and the TEP repair group. The mean length of surgical time was 69 minutes for the TAPP group and 74.0 minutes for the TEP group with (CI – 0.3 to 2.6)This suggests that the operative time is shorter in the TAPP repair group when compared with the TEP repair group. (figure 2)

POSTOPERATIVE PAIN Ten studies reported post-operative pain after hernia repair at 24 hours after surgery. Pain score was calculated in these studies using a visual analog scale. The data of 787 patients revealed no significant differences in pain scores at 24 hours postoperatively between TAPP and TEP repair groups (CI- 0.6 to 2.6), However, the evidence showed lower post-operative pain scores after TEP repair than TAPP repair. (figure 3)

LENGTH OF HOSPITAL STAY. Ten studies reported on the length of hospital stay between TAPP repair and TEP repair. The data from 705 studies revealed significant differences between TAP repair and the TEP repair group(CI – 0.6 to 2.2). This suggests TEP repair group had shorter hospital stays than the TAPP repair group. (figure 4

The goal of inguinal hernia surgery is to restore the anatomical parts of the inguinal canal and offer long-term alleviation of related symptoms. Due to its reduced risk of local complications, quicker recovery time, and lower pain scores, less invasive techniques are becoming increasingly used [21,22,23]. Even while earlier meta-analyses found no appreciable differences in the clinical results of these laparoscopic hernia repair techniques, the current systematic review and meta-analysis, which included more recent and larger RCTs, demonstrated the benefits of TEP and TAPP repair. The current meta- analysis discovered that TAPP repair had the benefit of a shorter surgical time. The TEP group showed less postoperative disco mfort and a shorter hospital stay. During the first week following surgery, there was a substantial difference in the pain scores. The TEP groups pain scores at three and six months were similar with time and pain reduction, presumably as a result of the extraperitoneal approach's correlation with decreased peritoneal irritation. The parietal peritoneum is sensitive to pain, warmth, touch, and pressure, as demonstrated by the innervation of the T7– T12 and L1 spinal neurons as well as the obturator nerve [18,19]. Between the anterior abdominal wall and the parietal peritoneum, TEP repair is carried out. Lower pain scores may be explained by the fact that the peritoneum is not damaged, unlike in TAPP repair [15, 17]. Furthermore, it should be noted that peritoneal irritation following laparoscopic hernia repair is primarily a self-limiting condition, which explains the variations in pain ratings during the initial post-operative phase.

The results of the pain score are congruent with analgesic intake, a more objective and quantifiable criteria for assessing the intensity of pain.  Of the principal instances, the patients in the TAPP group required extra analgesics by a significant margin as compared to the TEP group. Analgesic consumption showed no difference between the two groups. Recurrence maybe as a result of prior surgery causing injury to some terminal sensory branches. The absence of information on the kind of prior surgical procedure these individuals had, however, is a study limitation.

The significant level of heterogeneity in this subgroup may be explained by the constraint. On the Among the major cases, the substantial variati on in hospital stay was in favor of TEP repair. There was a great deal           of

variation among the cases of recurrence. Furthermore, pain following surgery may be a closely related element among the several variables        that can influence a hospital stay [20].  Patients with recurrent hernias in the TAPP group had m uch shorter surgical times. It might be because the preperitoneal space is smaller and more difficult to dissect than the peritoneal cavity in the original anatomy, which makes space generation and maintenance in TEP repair more challenging due to scarring or stitches from prior repairs.

The comparative analysis indicates that surgeons who are proficient in repairing inguinal hernias using TEP should persist in doing so. On the other hand, the marginal outcomes also support the continuation of TAPP procedures, since there is insufficient evidence to indicate any long-term harm to the patient. Overall, the study is unable to recommend changes to current techniques; however, any surgeon who has the resources to do TEP or TAPP inguinal hernia surgeries ought to prioritize a TEP repair if it is not otherwise contraindicated, according to the evidence gathered. The community may now evaluate the benefits of each inguinal hernia repair method thanks to the study's findings. It may be explored whether strategy may assist particular patient demographics once it has been established that each is effective and poses little risk to the patient. To find out if each strategy produces positive results in populations such as the obese, elderly, or polymorbid, for example, more research can be done.

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